Spectrochemical Study of Microscopic Crystals. XVII. The Structure of Cupric Salts with Monocarboxylic Fatty Acids

Abstract

Abstract In order to examine the structure of cupric alkanoates, the dichroism in the visible and the ultra violet region has been determined by the microscopic method with normal butyrate, valerianate, capronate and caprylate of copper (II). Visible and ultra-violet absorption spectra in organic solvents and infrared absorption spectra in Nujol mulls have been determined with the above compounds, along with cupric palmitate and stearate. Iso-alkanoates have also been examined in a similar way. All these compounds in the crystalline state and in organic solvents are found to show similar absorption spectra having the dichroism with characteristics fundamentally similar to those of cupric acetate and propionate which had earlier been reported. From these results, it has been concluded that all the above compounds consist of the dimeric molecules. The anhydrous forms of the compounds have been shown to consist of the dimeric molecules resembling those of the hydrated form. All the above compounds show absorption bands at about 43 and 80×1013/sec. The former is polarized along the Cu(O)4-plane and the latter along the direction binding the two copper atoms in a molecule.